This is a decent example of this pontiled mineral water from Philadelphia. Circa 1855, it has an applied "hat" top, the classic Twitchell type. This is always a pontiled bottle, but it's unclear whether this example is because the pontil scar is obscured. See all pics please.
Embossed: TWITCHELL / T (open block letter) / PHILAD.A // SUPERIOR / T (open block) / MINERAL WATER
Color: teal green
Condition: Excellent structurally with just some spotty surface wear, patchy faint haze, and some areas of scratchiness. There is a flea bite nip off the top that you need to feel for., mentioned for accuracy.
Reference Number: X246